On the Battery Recharge Time in a Stochastic Energy Harvesting System

摘要

Systems harvesting energy from a stochastic source have been widely studiedin the literature. However, we are not aware of any work that deals with thetime it takes for a battery to recharge up to a given level, when the energysource is discrete stochastic. This letter aims to examine the recharge time ofa perfect battery. We examine the cases when the energy arrival is a Poissonprocess, and more generally, a renewal process. We obtain formulas for thedistribution of the recharge time as well as the expected value of the rechargetime. Using these, we find the switching time of the system, which is thenapplied to the design of a harvest-then-transmit protocol for greencommunications. Monte-Carlo simulations verify the obtained formulas.